Architecture: London: all wrapped up for Christmas: Jonathan Glancey welcomes the transformation of buildings into giant presents that outshine the Oxford Street lights. Georgia Glynn-Smith took the pictures

Christo, the Bulgarian-born artist, has spent the season before Christmas trying to convince members of the German parliament to let him wrap up the Reichstag building in Berlin next year; like some titanic Christmas present, the former and future home of the German parliament may yet be covered from pediment to base in a hi-tech version of silver paper.

The idea might seem bizarre, yet the wrapping of buildings is something done on a regular basis, especially at Christmas and not just by artists. A trip around central London this week reveals dozens of buildings wrapped and otherwise girdled round, many in seasonal dress. You will have noted others, I am sure, in other British towns and cities.

Some, such as the Imagination building in Store Street, off Tottenham Court Road, have been transformed into architecture's equivalent of the Christmas tree, while others - such as the St Pancras Hotel - threaten to outdo Christo (especially when giant video advertisements have been projected on to its temporary second skin).

Others, such as the Albert Memorial, are hardy perennials: rather like the giant Christmas tree presented by the Norwegian government each year to cheer up Trafalgar Square, or the West End lights, the endangered Victorian monument's gift wrapping has become a permanent fixture.

Elsewhere in the capital, County Hall, the former home of the Greater London Council and now being transformed into a 570-bedroom hotel for the Shirayama Corporation of Osaka, has been lit up for Christmas in a warm glow of red lights (by the Lighting Design Partnership). A number of other developers and contractors have gift-wrapped their latest bricks-and-mortar investments; a particularly fine example of a building hidden by what looks like smart Christmas wrapping paper can be seen in Regent Street, a few doors from Liberty.

The Imagination building really does look special on a cold, wet London evening. The Christmas tree treatment - presents made of neon tubes, what look like candle flames glowing high up on pilaster tops and a glittering star set in the pediment - is the work of Gary Withers, the managing director of Imagination.

Imagination is a design company specialising in exhibition and lighting design (it lit up the Lloyd's headquarters in the City of London and gave the Art Deco Hoover Building, now Tesco, on Western Avenue, its curious green glow). Withers's Christmas-tree look is simple and effective; the building's stepped Victorian facade has been transformed by a sleight of the designer's hand into a two-dimensional Christmas tree, a nice conceit because it suits the mood of the building well - thanks to Dickens, Christmas is very Victorian.

Withers's trick is, however, doubly clever because the red-brick Victorian front of the Imagination building is very much a facade - architectural wrapping paper; should you step behind the neon presents and red bricks, you will find not a Victorian office interior, but a dazzling hi-tech atrium - one of the most successful of its kind - designed by Ron Herron and completed four years ago. This is a gift of a building, wrapped seasonally and appropriately as a giant present.

The decision to press ahead with a full restoration of the exterior of the St Pancras Hotel, one of the world's finest Gothic Revival buildings (designed by Sir George Gilbert Scott for the Midland Railway) was made in recent months. When the wraps are taken off, the salmon pink brickwork and green-tiled roof will be revealed in all its brash Victorian glory.

This phantasmagoric building has always had the look of a Burne-Jones dragon; this Christmas it looks like a dragon slumbering in baggy pyjamas. Christo really will be hard pressed to rival St Pancras if he gets the go-ahead to wrap the Reichstag. In recent months, video advertisements have been projected on to the plastic wraps covering the pinnacled hotel; the effect is dazzling, although it has caused drivers to take their eyes off the busy Euston Road running in front of Scott's masterpiece. All the building needs now is a few special lighting effects - like the red filters placed across the floodlights at County Hall this Christmas - and its transformation into a giant artwork would be complete.

Another of Sir George Gilbert Scott's buildings - the Albert Memorial - has been under wraps for some years. The scaffolding resembles one of the ungainly American-style Post-Modern office blocks that spread across British cities in the late Eighties; it also looks a little like a floating wooden theatre that the Milanese architect Aldo Rossi built earlier in the Eighties and moored for some time beside the Salute church in Venice.

Unlike the Rossi theatre, the Eighties-style Albert Memorial looks a little gloomy; again, with some special lighting, it could be one of the new sights of London. But the wrapping here is the closest of all to that of a Christmas present; when finally removed, it will uncover one of the most extraordinary gifts made by Queen Victoria to London: a statue of the Prince Consort seated under the pinnacled and polychrome canopy of what looks a particularly outrageous Victorian carriage clock.

What these examples show is that the gift-wrapping of buildings under construction or in the course of restoration has become a minor art form, so much so that some buildings look best dressed in temporary wraps. Some contractors' hoardings - notably the one shown here in Regent Street and the one that hides the new British Library (next to St Pancras) - are a delight, offering passers-by information about the work sites and simply cheering up stretches of street that would otherwise look scrubby and dismal.

Certainly the best-wrapped buildings outdo the dismal traditional Christmas lights of Oxford Street and Regent Street. Perhaps next year, architects, developers and contractors up and down the country can be persuaded to take what looks to be a unselfconscious trend into a new and recognised form of Christmas decoration.

(Photographs omitted)